The present invention relates to: an end structure of a nozzle configured so that gas is injected into or discharged from a container containing an object; and a purging device and a load port each including a nozzle unit having the end structure.
There are containers such as a FOUP (front-opening unified pod) configured to contain wafers which are material for semiconductor devices. The internal space of such a container is purged with inert gas such as nitrogen gas to prevent contamination of wafers. For example, referring to an apparatus described in Patent Literature 1 (Japanese Unexamined Patent Publication No. 2011-187539), nozzles each having a gas-flow passage are brought into contact with the bottom of a FOUP to cause each gas-flow passage to communicate with a corresponding opening formed through the bottom of the FOUP. In this state, purging is performed.
If there is any gap between the nozzles and the FOUP during purging, gas leakage occurs. Therefore, the nozzles have to be brought into close contact with the FOUP. In view of the above, in Patent Literature 1, a rubber grommet is attached to each opening of the FOUP. Further, at an upper end portion of each nozzle, a lip-shaped protruding portion protruding upward is provided around the gas-flow passage. Each nozzle is configured so that its protruding portion is brought into contact with the corresponding grommet when the nozzle is moved upward. Because each grommet is made of rubber and soft, good and close contact is established between the protruding portion and the grommet at this time. With this, gas leakage during purging is prevented.